15 Sep 00 - CJD - Transfusions of blood can spread BSE

By Helen Rumbelow

Times ... Friday 15 September 2000

"mad cow" disease can be spread by blood transfusions , researchers said yesterday. A blood donation has passed the disease from a large mammal to another within the same species, strongly suggesting that the same is possible in human beings.

In Britain blood began to be treated last year to reduce the risk of variant Creutzfeldt-Jakob disease (vCJD), nine years after the first cases.

The findings raise serious doubts over the safety of blood transfusions in the Eighties and Nineties , because the infectious blood used in the research was from animals in the "incubation" period, which showed no sign of the disease.

The Department of Health said the risk remains "theoretical", however. "There remains no evidence that CJD or vCJD has ever been transmitted to humans through blood transfusion or blood products," a spokeswoman said. The research, funded by the Department of Health, was carried out by Chis Bostock, director of the Institute for Animal Health at Compton, Berkshire.

His team gave 19 sheep a pint of blood from other sheep that had been fed the brains of BSE-infected cows. One of the recipients developed the sheep-equivalent of vCJD two years later.

Professor Bostock said that the findings were so important that he wanted to publish them before the experiment had ended - it will take several more years for the results to be seen in both the recipient sheep and control groups.

Professor Bostock said that the research, published in The Lancet, was also exciting because if blood could be used to transmit the disease it showed that there were elements in blood that could be used as a test for the disease . The report was criticised by Paul Brown, senior research scientist at the American National Institute of Neurological Diseases in Bethesda, Washington, however. Dr Brown said that it was irresponsible to publish such early research, especially when no further precautions can reasonably be taken by the Government.

Research due next year into transmission from the blood of infected human beings to monkeys should give a better idea about the risk, he said.

There was hope that there would be a blood test for vCJD in about a year or so , he added. The National Blood Service in Britain began a process on all donated blood last yearto remove most of the white blood cells, because they can carry infection.

This came after experiments in rodents which showed that when white cells were removed their blood could not be made to transmit vCJD.

15 Sep 00 - CJD - BSE restrictions may be relaxed

James Meikle

Guardian ... Friday 15 September 2000

A key public health measure designed to prevent people from catching the human form of BSE from infected cattle may be relaxed within 18 months, the government's food standards agency hinted yesterday.

The rule that bans nearly all meat from cattle over 30 months old entering food could be gradually phased out from early 2002, providing there is a tightening of other controls, including the cattle passport scheme that details the animals' movements from birth to slaughter.

The agency's draft review of anti-BSE controls is the first official document to set a possible date for phasing out the most expensive of all the measures forced on the government . It was meant to retain consumer confidence in beef following the revelation in March 1996 that people were probably dying from eating infected meat in the late 1980s. The government's scientific advisers on BSE and its human equivalent, vCJD, will consider the agency's paper this month.

But the agency is also gloomy about the prospects for the sheep industry if current experiments demonstrate BSE has transferred into the 40m national flock. Studies of how the disease works in sheep have suggested it would be impossible to remove all potentially infective tissue as is done in all cattle going into food.

Although the agency does not explicitly say so, that could mean having to import huge amounts of lamb to sustain a consumer demand until new breeding techniques to develop BSE resistant sheep and tests to diagnose BSE in live sheep could be developed. Both are years away.

Nearly 4.5m cattle over 30 months old have been slaughtered, with farmers getting £1.4bn compensation. The rendered down remains are stored in depots awaiting incineration , and it could be four years before the backlog is cleared. This has so far cost £575m, although some of this is recovered from Brussels.

The agency has felt able to contemplate relaxing the rule because of the sharp fall in the number of BSE cases in cows, about 760 cases so far this year compared with 36,000 a year eight years ago. By 2002 numbers may have fallen to levels that take Britain out of the highest BSE risk category set by EU vets. No other country, even with BSE, has an age limit on cattle used for food.

The average incubation period for BSE in cattle is thought to be five years so it will be the middle of next year before it is clear whether strengthened controls on animal feed also introduced in 1996 have worked. So far only one animal born after that date has succumbed to BSE in Britain although it is not clear what the cause was. Experts think there might be a few more cases although they hope the cause is transmission from their mothers, not breaches of the feed controls.

The agency is to reconsider the 30-month rule next autumn and has suggested a decision might be made by January 2002.

15 Sep 00 - CJD - CJD fear over blood donation grows

James Meikle and James Meek

Guardian ... Friday 15 September 2000

Fears that unwitting carriers of the human form of BSE might have infected patients via blood transfusions were strengthened last night with the publication of evidence from laboratory tests on sheep.

The results suggested that blood of an infected animal can transfer BSE-like disease to another long before it displays outward signs of the condition, and appeared to confirm the prudence of human blood donation controls introduced last year.

Scientists from the institute of animal health, based in Compton, Berkshire, and Edinburgh, took the rare step of publishing the work in a medical journal, the Lancet, within weeks of the discovery because of its importance. Only last month researchers based in London suggested that their work, using hamsters and mice, raised serious questions about how animals thought to be healthy and incapable of acquiring BSE could in theory pass the disease on.

Variant CJD, which has so far claimed 82 victims in Britain, is now widely regarded as BSE in human guise . In another development scientists in Paris today claim a breakthrough in the struggle to understand how BSE-like diseases attack the brain, leading to hopes that treatment for the incurable condition may be on the distant horizon.

The scientists involved in the sheep experiments fed animals with cattle brain infected with BSE and, before they displayed any symptoms, transfused blood into healthy sheep imported from BSE-free New Zealand. The one sheep to have so far shown signs of BSE began displaying the symptoms 610 days after transfusion. The donor sheep had eaten the BSE material 318 days before the transfusion but did not display signs of the condition for a further 311 days, indicating the blood had been infective halfway through incubation.

All UK blood has to be filtered so the white cells thought most likely to carry vCJD are removed. Plasma used in blood products is imported from countries where there is no evidence of vCJD. The measures cost the NHS £80m last year.

The government insisted last night this was a precautionary safeguard to counter a theoretical risk and there remained no evidence that vCJD "has ever been transmitted to humans through blood transfusion or blood products".

The scientists warned their report "suggests that blood donated by symptom-free vCJD-infected humans may represent a risk of vCJD infection among the human population".

They had no evidence of levels of infectivity of pre-clinical CJD cases. But the presence of BSE activity in sheep blood suggested it would soon be possible to identify which blood cells carried the infectivity. This could help test the effectiveness of blood donation controls and develop tests for vCJD based on blood samples.

Colin Bostock, the institute's director, said: "This work shows it was prudent to take action against a theoretical risk."

The implications of the work, along with that of the London team, are to be studied by the government's advisers on BSE this month.

The Paris researchers studied prions, molecules of a chemical called PrP, which are thought, in abnormal form, to be closely associated with BSE-like diseases. Healthy humans manufacture PrP in their bodies but its function has been a mystery.

In an article in Science, scientists at the Pasteur institute and the Lariboisiere hospital argue it helps carry messages between nerve cells in the brain. Prions, abnormal PrP molecules, interfere with the process, leading to the crisis in the brain which is the beginning of CJD.

15 Sep 00 - CJD - Transfusion fears over spread of human BSE

By David Derbyshire, Science Correspondent

Telegraph ... Friday 15 September 2000

Fears that the human form of mad cow disease may have been transmitted through blood transfusions in the Eighties and Nineties are raised in a study today.

For the first time, scientists have shown that the infectious agent responsible for BSE is present in blood before symptoms of the brain wasting disease develop . Although the Government-funded study was carried out on sheep, its authors say it could have implications for the spread of variant Creutzfeldt Jakob disease, the human version of BSE.

They said: "Blood donated by symptom-free vCJD-infected human beings may represent a risk of spread of vCJD infection among the human population." The Department of Health said that, since 1999, all blood supplies used in Britain were filtered to remove possible BSE contamination.

The findings, published in The Lancet today, come from a study carried out at the Institute for Animal Health in Edinburgh. Sheep were deliberately fed with the brains of cattle infected with bovine spongiform encephalopathy. A year later, before any sheep showed signs of disease, a pint of blood was taken from each of the 19 animals and transfused into healthy sheep from New Zealand.

Within two years, one of these sheep began to show signs of BSE, the team led by Dr Fiona Houston found. Although the study has many years to run, the institute believes that the result was important enough to release it early. "Although this result was in only one animal, it indicates that BSE can be transmitted between individuals of the same species by whole-blood transfusion ."

Variant CJD is thought to be caused by an infectious agent known as a prion protein. In July 1998 the Government's expert panel on BSE and vCJD, the Spongiform Encephalopathy Advisory Committee, warned that there was a risk that the agent could be transmitted in white blood cells, or leucocytes. The National Blood Service introduced a screening programme for blood and now filters out white blood cells. Plasma from British patients is no longer used to make blood products.

Prof Colin Bostock, director of the Institute for Animal Health, said the study had confirmed the 1998 decision. He said: "This particular animal was one of the first to be studied and it's one of the first to go down. Whether any of the other animals will succumb is unknown."

No one knows how many people are incubating vCJD or how long the incubation period is. So far, there have been 82 probable or confirmed cases. One of the early victims of vCJD was Maurice Callaghan, an engineer from West Belfast who died in 1995. After his death, it was confirmed that he had been a regular blood donor . Other known victims are also likely to have given blood .

The Department of Health is asking the BSE panel to examine the evidence at its next meeting at the end of the month. spokesman said: "There is no evidence that CJD or variant CJD has ever been transmitted to humans through blood transfusions or blood products."

14 Sep 00 - CJD - CJD could be passed on when carriers give blood

By Steve Connor, Science Editor

Independent ... Thursday 14 September 2000

People infected with the human equivalent of "mad cow" disease who have yet to show symptoms could pass on the infection through blood transfusions , a study published today has concluded.

Scientists have shown it is possible to transmit bovine spongiform encephalopathy (BSE) from sheep incubating the disease to healthy sheep.

In Britain, an unknown number of people who are seemingly healthy are infected with the agent that causes variant Creutzfeldt-Jakob disease (vCJD), which scientists have described as "human BSE".

A study published in The Lancet, led by Christopher Bostock, the head of the Institute for Animal Health, found that one sheep out of 19 that had received blood from sheep deliberately fed BSE material developed the symptoms of mad cow disease.

"This report suggests that blood donated by symptom-free vCJD-infected human beings may represent a risk of spread of vCJD infection among the human population in the UK," the scientists say.

These findings have been rushed into print to allay fears of a cover-up at the end of the experiment in three years.

Dr Bostock said it was not known which part of the blood contained the infectious agent, but all the evidence pointed to the leucocytes , the white blood cells that are now filtered out during human transfusions.

"When vCJD was first identified and people started thinking about the consequences for human health, and in particular blood transfusions, the procedures put in place to reduce the risk assumed a theoretical possibility that blood would be infectious during the incubation period," said Dr Bostock. "This work shows that the measures that were taken were entirely appropriate."

The Department of Health said yesterday that all blood transfusion products were made from plasma imported from countries with no BSE.

12 Sep 00 - CJD - Fears over French BSE

By Patrick Bishop in Paris

Telegraph ... Tuesday 12 September 2000

A livestock screening programme launched by the French government in July is revealing disturbing levels of BSE among French cattle .

Early results show that up to two cows in every 1,000 tested have the disease. The figures suggest that official statistics on the progress of BSE in France have underestimated the extent of the problem. Researchers discovered eight cases of BSE among the 4-6,000 cattle tested after having died under suspicious circumstances. The programme aims to examine 48,000 cattle.

The Figaro newspaper said yesterday that, if confirmed, the first results would suggest that 1,200 infected cows escape detection and are passed fit for human consumption each year .

But Prof Jeanne Brugère-Picoux, a leading vet, said: "This is based on an erroneous extrapolation. You have to emphasise that these tests are being carried out on animals which have already been identified as being at risk. If we carried out tests on animals going to the abattoir, the results would be much more reassuring for the consumer." So far 42 cases of BSE have been detected in France this year. Britain has recorded 176,000 cases of BSE.

11 Sep 00 - CJD - BSE 'worse than believed in France'

by Ian Sparks in Paris

Evening Standard ... Monday 11 September 2000

A national programme of BSE tests on French cattle has revealed mad cow disease is up to four times more prevalent than had been previously thought .

However, a French agriculture ministry spokesman said: "Just because we have BSE in France, it does not make British meat any safer.

"We will comment when the entire programme is completed. Whatever the results, it does not mean we will be lifting our import embargo on British beef."

Early findings of France's nationwide survey have found between 1.5 and two cows per 1,000 are infected . It could mean more than 1,000 of the three million cows eaten in France every year are contaminated .

The programme, which began in June, will see 48,000 cattle tested by December. The preliminary findings were leaked to a French newspaper by vets connected with the project. A source revealed: "The early results basically suggest beef is not as safe to eat in France as we lead ourselves to believe ."

France banned nerve tissue, ground bone and other organs from being used in French cattle feed in 1990, hoping a diet of uncontaminated meal would eventually eradicate the disease.

They also introduced tough culling measures in 1996, killing the whole herd if a single cow caught BSE.

France is facing prosecution in the European court after refusing to obey a Brussels ruling to lift its embargo on British beef a year ago.

11 Sep 00 - CJD - Imperial lure top Oxford brains

by Joel Wolchover, Education Correspondent

Evening Standard ... Monday 11 September 2000

London's Imperial College is celebrating after recruiting three of Oxford's top scientists and their research teams for a new £30 million institute devoted to the study of infectious diseases, including BSE , meningitis and Aids.

The university has persuaded the professors, including one of the country's leading experts on the BSE epidemic, to leave their posts and bring with them around 80 researchers .

Professors Roy Anderson , Geoff Smith and Brian Spratt will move into the refurbished medical school building at St Mary ' s Hospital in Paddington, where Alexander Fleming discovered the antibiotic properties of penicillin.

More than £10 million has already been spent creating the new Wright-Fleming Institute, and a further £20 million from the Government and the Wellcome Trust has been earmarked for the centre, which will specialise in infection and immunology.

The institute is part of a £300 million initiative to create a "super hospital" on the St Mary's site, which will be able to compete internationally for funding and the best researchers.

Oxford academics are a prime target , not least because the site is next to Paddington station, making it an easy commute to and from the dreaming spires.

Professor Jonathan Weber, who will head the institute, said: "This is a very exciting development for Imperial College. Scientists only move if they think their work is going to be improved by doing attractive, and that is why we have been able to attract these people, who are all top-class researchers."

Professor Anderson , former director of the Wellcome Trust Centre for the Epidemiology of Infectious Diseases at Oxford, is a renowned research scientist who has advised the Government on BSE and Aids.

His damning evidence to the recent BSE inquiry accused the Ministry of Agriculture of withholding vital data which could have helped researchers to identify and tackle the outbreak more quickly.

Professor Anderson is a Fellow of the Royal Society, Britain's scientific elite, as is Professor Spratt , a professor of microbiology at Oxford. He is an expert in biological warfare and led an inquiry into the effects of depleted uranium on Gulf War veterans.

The third of the Oxford trio is Geoff Smith , professor of virology at the university's department of pathology. He will hold the same title at the institute.

Imperial is a college of the University of London and has established itself in recent years as one of the country's leading universities and a world-class centre for scientific and medical research.

It already attracts more research funding than any other university, and unofficial newspaper league tables have for the past two years ranked Imperial in second place, above Oxford and only narrowly below Cambridge, for research in science, technology and medicine.

09 Sep 00 - CJD - Meat eating questions for villagers

James Meikle

Guardian ... Saturday 9 September 2000

Some 1,100 households in Queniborough, Leicestershire will today get questionnaires on their shopping and eating habits during the 1980s , as doctors continue investigating an apparent cluster of five victims of vCJD, the human form of BSE.

Of the five, three died in 1998 and certainly had links to the village, while a 19-year-old about whom few details have been made public died this summer in Leicester, and another probable victim of the incurable disease, still alive, once lived at neighbouring Rearsby.

The questionnaires, distributed with the parish newsletter, are part of a concerted attempt to find out if the concentration of cases is significant. Inquiries might go on to December, and further questionnaires are likely .

Philip Monk, a consultant in communicable diseases, said: "We are asking whether they have children born between 1960 and 1980 . Then we are asking what their shopping habits were, and where did they buy meat during the 1980s. While we are concentrating on meat , that does not mean it will end there." At a parish council meeting last month, villagers had said they wanted to do all they could to help.

Since May 1995, there have been 74 deaths in Britain, 19 so far this year, from vCJD. Eight other probable victims remain alive.

05 Sep 00 - CJD - Rising death toll from human BSE

James Meikle

Guardian ... Tuesday 5 September 2000

Nineteen people have died from the human form of BSE in Britain this year, already making it the worst year since the outbreak started in May 1995 .

Four victims died last month, and another eight are suspected of having the incurable disease, formally known as vCJD. The death toll now stands at 74 .

The increase apparently confirms a rapid acceleration in the disease which experts believe has been growing at 20-30% each year , although its spread has been disguised by the time from victims first showing symptoms to their deaths varying from seven months to more than three years.

It is not known how long the victims were incubating the disease before symptoms were noted, although most were presumed to have been infected by cheap cuts from cattle before parts of the animals thought most risky to human health were banned from food in late 1989.

However, the BSE inquiry due to report next month is expected to criticise both government officials and ministers for not taking the threat seriously enough and ensuring that measures were not flouted in the years before the probable link between early deaths and cheap meat was established in March 1996.

Scientific advisers will this month consider whether extra controls to protect food and prevent accidental transmission of the condition through surgical operations are needed. Research published last month indicated that both BSE and vCJD may be highly infectious even when unknowing carriers of the disease display no outward signs.

Three people died from vCJD in 1995, 10 in both 1996 and 1997, 18 in 1998 and 14 in 1999.

03 Sep 00 - CJD - BSE Report 'To Criticise Tory Ex-ministers'

From the Press Association

Guardian ... Sunday 3 September 2000

Conservative former ministers and Whitehall officials face strong criticism in the official report into the BSE crisis.

The inquiry chairman Lord Phillips is believed to have notified several former health and agriculture ministers that they are facing criticism in the 13-volume report he is to publish in a few weeks.

Reports in several Sunday newspapers suggest the former ministers will be taken to task for being too adamant in their assurances that British beef was safe, and for failing to react swiftly enough to scientists' findings that the disease could spread to humans.

Scientists first suspected that there was a risk to humans eating BSE-infected offal in the mid-1980s , but it was not until March 1996 that Tory ministers admitted that there was a danger to the public.

But the ex-ministers could come off lightly compared with senior civil servants who ran the two departments as the decade-long saga unfolded.

Lord Phillips' two-year inquiry is said to have concluded that too much importance was attached to the interests of the livestock industry , and not enough to those of consumers .

The BSE affair led to a worldwide ban on British beef exports which is estimated to have cost the taxpayer £4.6bn .

03 Sep 00 - CJD - BSE inquiry will censure Tory ministers

Jonathon Carr-Brown and Michael Prescott

Sunday Times ... Sunday 3 September 2000

The official report into the BSE crisis will criticise former Tory ministers , including John Gummer , for being "too adamant" in their assurances that British beef was safe.

Gummer, the former agriculture minister, became notorious for feeding his daughter a beefburger in front of press photographers.

The criticism will be made despite intensive efforts by Gummer and other former ministers to get the report watered down.

Former Conservative ministers, including Kenneth Clarke , who was health secretary, Lord Freeman , a former health minister, Douglas Hogg , a former agriculture minister and David Maclean and Angela Browning , both former ministers of state for agriculture, have received notification from Lord Phillips, the inquiry chairman, that they may be criticised in the 13-volume report that he is to publish at the end of this month.

Sources close to Phillips say he has refused to get bogged down in a fight with the former ministers or to make all the changes requested. The former ministers are, however, said to come off lightly compared with official s who ran the health and agriculture departments as the 10-year BSE saga unfolded.

The indications are that Keith Meldrum , chief veterinary officer at the agriculture ministry, will be particularly criticised for putting the interests of the livestock industry before those of the consumer .

Sir Richard Packer , former permanent secretary at the ministry, will be criticised for failing to ensure that the order not to put bovine products in feed was rigorously adhered to and that orders telling abattoirs to strip carcasses of offending material were carried out.

In 1995, six years after a ban was placed on the sale of high-risk bovine offal, Packer had a heated row with Dr Robert Kendell , Scotland's former chief medical officer, after carcasses were found en route to butchers with their spinal cords in place.

Civil servants from the Department of Health, like the politicians, will also be criticised. In particular Sir Donald Acheson , chief medical officer from 1983 to 1991, is likely to be criticised for not being cautious enough.

The official inquiry report into the BSE crisis will strongly criticise John Major's government for failing to react swiftly enough to scientists' findings that the disease could spread to humans.

A senior figure, who was questioned by the inquiry, has told The Telegraph that the report says it took too long for the dangers of BSE to be acted upon. "There is a sense that the message took too long a time to filter through the bureaucracy ," said the senior Conservative Party figure who has seen draft passages of the report. "The inquiry believes that the issue should have been handled with a greater sense of urgency ."

The report, to be published next month, is expected to be particularly critical of the role played by the Ministry of Agriculture during the crucial years leading up to the official announcement of a suspected link between BSE in cattle and a new form of CJD in March 1996. Scientists first suspected there was a risk to humans eating BSE-infected offal in the mid-Eighties , but it was not until March 1996 that Tory ministers admitted that there was a danger to the public.

The inquiry, which opened two years ago, is expected to criticise the Tory administration for allowing offal to enter the food chain after it was banned and then passing the buck as ministers and officials blamed local authorities for failing to enforce slaughterhouse controls. Former ministers and civil servants from the Major years are bracing themselves for the publication of the report by the inquiry's chairman, Lord Phillips.

Taxpayers will pick up the £7 million bill for the legal advice given to Ministry of Agriculture ministers and officials questioned by the inquiry. The inquiry itself has cost £16 million.

Douglas Hogg , the former agriculture minister, and Sir Richard Packer , 55, who was handed a reported £400,000 pay-off last year from his post as the Agriculture Ministry's chief civil servant, have been warned that they face "potential criticism". The affair led to a worldwide ban on British beef exports which is estimated to have cost the taxpayer £4.6 billion .

01 Sep 00 - CJD - CJD causes woman's death

Staff Reporter

Metro ... Friday 1 September 2000

A woman has died from suspected new variant CJD, the human form of BSE. An inquest on Catherine Stevens, 31, was opened and adjourned by the Walsall coroner Aidan Cotter. Miss Stevens died at her home in Walsall a week ago.

Pathologist Dr. Martin Carey said the provisional cause of death was acute pyelitis - a severe form of blood poisoning - and new variant Creutzfeldt-Jakob disease.

Deaths from CJD in Britain have risen from 3 in 1995 to 14 in 1999 .

30 Aug 00 - CJD - Stricter surgery rules to counter fears of CJD

By Valerie Elliott, Countryside Editor

Times ... Wednesday 30 August 2000

Surgical instruments used in tonsil, appendix and brain operations are to be destroyed after one use in controls planned by the Department of Health to limit the potential spread of the human form of BSE .

Pat Troop, the Deputy Chief Medical Officer, is working with government scientific advisers to draw up a list of operations and medical procedures in which instruments must be used once only .

The move is set to cost millions of pounds but ministers believe that they must take every possible precaution to prevent the risk of patients contracting variant Creutzfeldt- Jakob disease (vCJD).

A report from a panel of experts from the BSE committee, the Spongiform Encephalopathy Advisory Committee (SEAC), and the Advisory Group on Dangerous Pathogens, assessing the number of operations and likely cost of the move, is to be sent to ministers within weeks.

The "once only" rule has been mooted before but so far has been considered too expensive. The Department of Health has also issued a recent reminder to hospitals and opticians to ensure that the lenses on optical equipments are used once only.

The possible transmission of vCJD via surgical equipment is also highlighted in new research from scientists led by one of the country's leading experts on the disease, Professor John Collinge, which shows that the disease can jump between species more easily than supposed and that humans could also theoretically contract the disease from sheep, pigs and poultry .

The Government yesterday tried to play down fears of a new BSE scare. A spokesman said safeguards were already in place to counter the possibility of "subclinical" forms of the disease in which stricken animals appeared healthy.

The new research findings are to be studied by SEAC at its monthly meeting on September 29. Professor Peter Smith, SEAC's acting chairman, said yesterday: "We know a very large number of infected cows went into the food chain and were killed before they developed the disease, so there is infection we don't know about."

Dr Michael Clark, Tory chairman of the Commons Science Select Committee, said that publication of the research was unhelpful. "To bring out a statement of this type before it is really certain... is alarmist. It is quite possible that by being slack on sheep and pigs and poultry that we are harbouring and storing up for the future another catastrophe."

30 Aug 00 - CJD - There is nothing 'obscure' about mad cow disease

Julia Langdon

Guardian ... Wednesday 30 August 2000

Arrogant farming officials have learned little from the BSE crisis

The most extraordinary arrogance underpinned the comments of the spokesman for the National Beef Association, who yesterday sought to minimise the significance of the latest findings in the BSE scandal by questioning the conduct of research in what he described as "an obscure area". It was precisely that kind of arrogance within farming that in the first place produced this shameful outrage that has already killed 70 people and humiliated an entire industry .

The suggestion by Robert Foster, speaking on behalf of the country's troubled beef farmers, was that the incidence of BSE in cows is now diminishing, that the number of cases of new variant CJD in humans might therefore also be expected to reduce in number in future and therefore that we can all get back to our roast beef and Yorkshires and relax in the comfortable knowledge that these issues are being handled by people with a greater expertise than ourselves. Butchers can get back to such business as they have been bequeathed by the deadly combination of supermarkets and food poisoning, the scientists can cheerfully forget about these unnecessarily alarming matters and perhaps occupy themselves with something more socially useful, while the environmental lobby can get back in its box.

Yet it was the arrogant pursuit of profit to the exclusion of all other considerations which led an over-confident beef industry to feed ground-up dead sheep to herbivorous cows and cause this chaos. It was an arrogant complacency within farming which accepted for years the existence of scrapie in sheep without bothering to worry about the potential for this disease to cross into other animals. It hadn't happened - so why should it ? The incidence of human CJD caught from scrapie in sheep was known, but very rare. So, arguably, that particular complacency was justified - at least until the greedy farmers tried to maximise their profits by so unthinkingly causing the contamination of the entire beef industry and feeding diseased sheep carcasses to cows .

Now when it is revealed as a result of serious scientific study by the government-funded Medical Research Council that it is possible that a highly infectious variant of BSE could exist in another form in other species - sheep and pigs and poultry - someone speaking on behalf of the beef industry has the temerity to suggest that this is an "obscure " area for inquiry. It will not seem obscure to those relatives of innocent victims who have already died. In due course, it won't seem obscure either to any of that unknown number who may still be carrying the infection. And it doesn't seem obscure to me, a consumer . I want to know about these things.

My interest is no different to that of any other consumer, except that in the late 1980s I contracted food poisoning when pregnant as a result, presumably, of inefficient - or at least inappropriate - farming practices. In our case it was listeria monocytogenes and, mercifully, my baby and I survived. At the time, no one had heard of listeria, including the midwives in the maternity hospital. I watched my diet with great care and attention as any pregnant woman would. Although things had been a bit touch and go at the time of the birth - an emergency caesarean, intensive care, isolation wards, three weeks in hospital - I still hadn't realised quite how serious it all was until I had a visit from an official at the Public Health Laboratories. A man with a briefcase in due course arrived, exuding official assurances, to ask me about my diet. The baby had been born, three weeks early, in June; the official came to call in September and it was then that he wanted to know all that I had eaten in May. He wanted to know everything. If I had sausages, where would I have bought them? Did I wash my lettuces? Did I like cheese? What brand of butter?

My point in rehearsing this personal experience is to relate the extent to which it heightened my awareness of how close, how casual, had been my brush with serious food poisoning. There had been 19 cases of the same strain of listeria that year - none of us ever having heard of it, of course - and a number of them had died, the man with the briefcase revealed. It made me very conscious indeed of the extent to which it was possible to poison oneself unknowingly.

So it was with great interest that I recall attending a press conference held jointly by the Department of Health and the Ministry of Agriculture on February 27 1989, at which it was announced that the government had ordered that ground-up bits of the spinal column of cows along with some other less appealing bits of the animal were in future to be banned not only from baby food, but from the entire food chain . That press conference was a revelation . I was ignorant enough to be astonished to learn that baby food was not made up of the finest minced rump steak - but that was completely incidental. The event was dominated by a series of question to officials about the chances of "mad cow disease", as we had just learned to call it, crossing into the human food chain. The message was, by and large, to forget it.

Time and again the officials present were challenged. They insisted that such a cross-infection was something about which we should not be concerned - and that, in any case, if there was to be a problem we would not know about it for 10 or 12 years. And so it proved. John MacGregor, the agriculture minister at the time, took pride then, as he still does (or is he demonstrating a measure of relief?) in the fact that he was prepared to go further than the official advice which was limited to merely restricting dubious beef bits in baby food . MacGregor extended it to all food despite the reservations of some of his officials at his readiness to go beyond scientific advice. And all praise to him.

But there was a complacency at large then, as there is still. There was great nervousness about the alarm that had been provoked in the public mind about the safety of our food. There is still. There are various points to be made about publishing the interim results of research of the kind we heard about yesterday. It is, for example, almost certainly unhelpful to the farming industry. Well, bad luck on them. Regrettably that industry has forfeited any right to take decisions involving public health on our behalf . Isn't it actually more likely to be a source of public confidence rather than anything else that scientists are still monitoring what is going on in agriculture as a result of the industry's past mistakes and mismanagement ?

And so what if publication, unaccompanied by appropriate advice, is alarmist, as was also suggested yesterday. As the chairman of the Science and Technology Select Committee, Michael Clarke said: "If the whole country has to go vegetarian, then for goodness sake say so." That is one response. But the most important thing is that we, as consumers, should be alerted to what is going on and given the the information that enables us to take our own decisions, unfettered by other people's commercial concerns .

30 Aug 00 - CJD - Food safety chief plays down study on 'hidden' BSE

By Jackie Storer

Independent ... Wednesday 30 August 2000

The head of the Food Standards Agency says there is no need to introduce further BSE controls despite warnings that the disease may jump more easily than previously believed from one species to another.

Professor Sir John Krebs gave the reassurance last night in response to claims that other animals could harbour the disease without any symptoms. He said there was no need for people to change their eating habits in response to the findings.

Sir John, chairman of the agency, also said the study had no new evidence that BSE was entering the food chain.

Scientists led by Professor John Collinge said that not only cattle, but sheep , pigs and poultry exposed to BSE via animal feed may have developed a "subclinical" form of the disease that remained symptom-free and hidden.

Animals thought to be healthy and incapable of acquiring BSE could in theory pass on the disease to humans .

The agency welcomed the study, which it said needed to be considered by the agency's advisers on the Spongiform Encephalopathy Advisory Committee on 29 September before being made public. Sir John said: "However, we do not believe there is any immediate need to introduce further controls given that existing ones are already very extensive.

"The new study on its own does not provide any evidence of BSE entering the food chain . Nor is there any evidence of BSE infection spreading through pigs or poultry. What the study does do is support the precautionary approach being taken to protect public health."

The agency argued that the possible presence of infectivity in apparently healthy animals was already taken into account in present controls.

These include removing specified risk material (SRM) from cattle and a ban on the sale of beef from any bovine older than 30 months. SRM controls also apply to sheep as a precaution, but no sign of BSE in sheep has been found. Testing on sheep continues.

News of the research came as a man was critically ill in hospital after contracting the human form of mad cow disease. The man, whose name and age are not being released, is being treated in the Princess Royal Hospital, Telford, Shropshire.

29 Aug 00 - CJD - Government plays down new BSE threat

Staff and agencies

Guardian ... Tuesday 29 August 2000

Ministers today played down fears of a new BSE scare after warnings that the disease may jump from one species to another more easily than was previously supposed .

The Ministry of Agriculture, Fisheries and Food and the Department of Health said safeguards were already in place to counter the possibility of "subclinical" forms of the disease being present in animals which appear healthy. But relatives of victims of variant CJD, the human form of BSE, expressed concern at the findings.

The warning came from scientists led by John Collinge, who said not only cattle , but sheep , pigs and poultry exposed to BSE via animal feed, might have developed a hidden form of the disease . Animals thought to be healthy and incapable of acquiring BSE could theoretically pass the disease to humans .

Members of the government's spongiform encephalopathy advisory committee are to consider the findings at their next meeting on September 29, where they will question Professor Collinge.

The research was published today in the journal Proceedings of the National Academy of Sciences. In experiments, scientists infected laboratory mice with hamster scrapie, a BSE-like disease. Ordinary mice have always been thought to put up an effective barrier against this disease.

As expected, the mice showed no apparent signs of illness. But on closer inspection the researchers found they had high levels of potentially lethal abnormal proteins, called prions, in their brains . The researchers also showed that this subclinical infection could easily be passed on when injected into healthy mice and hamsters.

The fear is that what is true for hamsters and mice may also be true for cattle and other animals with BSE, and humans with vCJD. Prof Collinge said the research raised the possibility, "which has been mentioned before, that apparently healthy cattle could harbour, but never show signs of, BSE".

The results also raised another fear, of CJDbeing transmitted from seemingly healthy hospital patients through surgical equipment .

At present no cattle over the age of 30 months are allowed to enter the human food chain, and high-risk tissue such as the brain, spinal cord and spleen is banned from meat products. Since 1996 it has been illegal to give cattle feed that contains cow and sheep remains.

Variant CJD is thought to have spread to the human population through people eating contaminated beef products in the 1980s. A total of 79 cases have been recorded so far.

Frances Hall, secretary of the Human BSE Foundation, whose son Peter died from variant CJD in 1996, said: "We have always been worried that BSE might be in animals that aren't showing any symptoms. Subclinical animals can look perfectly fine, as can victims of human BSE before they get unwell."

29 Aug 00 - CJD - The threat to humans from BSE

Mark Tran and Julian Glover

Guardian ... Tuesday 29 August 2000

Scientists have reported that Creutzfeldt-Jakob disease (CJD), the human variant of mad cow disease, may be highly infectious even when its unwitting carriers do not display outward signs of suffering from the condition.

What is BSE?

bovine spongiform encephalopathy is a slowly progressive and ultimately fatal neurological disease affecting cattle. Commonly known as mad cow disease, it was first identified in 1986. CJD is the human form of spongiform encephalopathy and is caused by eating beef infected with BSE.

What causes BSE?

BSE in the UK comes from using animal feed containing contaminated meat and bone meal as a protein source. Health officials suspect that cattle were contaminated by either scrapie-affected sheep or cattle. Scrapie is a fatal, degenerative disease affecting the central nervous system of sheep and goats.

What is the likelihood of catching BSE?

The information keeps changing. In the latest scare, Professor John Collinge says new research shows that animals thought to be healthy and incapable of acquiring BSE can in theory pass the disease on. Experiments on mice and hamsters have suggested that similar diseases could jump between species more easily than previously thought. His findings have sparked renewed concern that humans not displaying variant CJD symptoms but incubating the condition may infect others during medical or dental procedures.

Has there been a recent outbreak of CJD?

Health officials are investigating a cluster of five cases around Queniborough, just north of Leicester. These included three victims dying within a few of months in 1998, a fourth who died in May 2000 and another patient, still alive, who is thought to be suffering from the disease. However, it is worth remembering that only 70 people have died of vCJD.

Are people still being infected?

This is what perplexes scientists. Until today's findings, the prevailing scientific opinion was that humans were almost certainly not still being infected. The government's expensive programme of slaughtering all cattle aged over 30 months and - temporarily - banning the sale of beef on the bone minimised public exposure to BSE-infected meat and was thought to have caused the disease to almost die out in Britain's beef herds.But the latest research published by the National Academy of Sciences will cause a rethink.

What did the latest research involve?

Prof Collinge's team found that mice injected with hamster scrapie, a BSE-like disease, carried high levels of infectivity while living into old age without outward symptoms. But when material from the brains of these mice was injected into other mice, it eventually killed them. The worry is that the process created a new strain, or strains, of a more virulent disease .

Do the latest findings contradict recent information?

They do seem to go against research released only earlier this month, when scientists said CJD could ultimately claim 136,000 lives , a much smaller number than previous estimates. At one point there seemed to be no limit to the numbers potentially at risk. A European committee thought that a single animal with BSE could put up to 500,000 people at risk.

Why were the numbers revised?

In a report in the journal Nature, scientists from Oxford concluded that any sick animal that entered the food chain was liable to infect no more than two individuals, and only 40% of the population was genetically susceptible, leaving the incubation period as the other key factor. If the incubation period was less than 20 years, there could be as few as 63 cases. If the incubation period stretched to almost lifetime length - 60 years - then there were likely to be 136,000 . What matters over the next few years is the annual rate of increases. "If the average annual incidence of CJD over the next three years is fewer than 15 cases, then the maximum total number of cases would fall to 20,000," they wrote.

How did the government deal with the BSE crisis?

Many people think that the issue could have been addressed far earlier . BSE was identified in November 1986 but ministers were not informed about the disease until June 1987. Although measures were subsequently put in place to keep meat most likely to be infected away from the dinner tables, it was not until 1996 that the government admitted that there might be a serious risk to human health. The Labour government launched an official inquiry into the way the crisis was handled which is now under way.

The head of the Food Standards Agency insists there is no need to introduce further BSE controls despite warnings the disease may jump from one species to another more easily.

Professor Sir John Krebs gave the reassurance in the wake of claims that other animals could harbour the disease without showing any symptoms.

He stressed that there was no need for people to change their eating habits in response to the findings. Sir John, chairman of the FSA, also claimed the study provided no new evidence that BSE was entering the food chain.

(UK Correspondent's note: hundreds of thousands of cattle slaughtered at enormous cost, 80 human dead already and predictions of at least 136,000 in all, and MAFF & DoH are still issuing fatuous platitudes. Cattle are stripped of SBO, sheep too but the lymph glands are more widely spread and cannot be eliminated, there are no measures at all for pigs or poultry. Meat & bonemeal based fertiliser is banned on crops for animal consumption - but not for crops destined for humans!)

Scientists led by expert Professor John Collinge said that not only cattle , but sheep , pigs and poultry exposed to BSE via animal feed may have developed a "subclinical" form of the disease which remained symptom-free and hidden.

Animals thought to be healthy and incapable of acquiring BSE could theoretically pass the disease on to humans, according to the published in the journal Proceedings of the National Academy of Sciences.

The FSA welcomed the scientific study which it said needed to be carefully considered by the Agency's expert advisers on the Spongiform Encephalopathy Advisory Committee (SEAC) on September 29 before being made public.

Sir John said: "However, we do not believe there is any immediate need to introduce further controls given that the existing ones are already very extensive.

"The new study on its own does not provide any evidence of BSE entering the food chain . Nor is there any evidence of BSE infection spreading through pigs or poultry . What the study does do is support the precautionary approach being taken to protect public health."

The FSA argued that the possible presence of infectivity in apparently healthy animals was already taken into account in the current controls. These include the removal of Specified Risk Material (SRM) from cattle and a prohibition on the sale of beef from any bovine aged over 30 months.

SRM controls also apply on a precautionary basis to sheep, although no evidence of BSE in commercial sheep has been found. Testing on sheep continues. BSE controls are currently the subject of a comprehensive public review being carried out by the FSA

29 Aug 00 - CJD - BSE revelation confirms worst fears

James Meikle

Guardian ... Tuesday 29 August 2000

Quandary for ministers over preventive measures as research challenges previous assumptions on characteristics of fatal disease

The revelation that BSE and its human form may be able to jump the species barrier and be highly infective even when a person or animal with the disease shows no signs of it, appears to confirm some of the worst fears scientists have about the fatal condition.

The disease, bovine spongiform encephalopathy, has already caused a cattle epidemic costing more than £4bn, and its human toll of 73 deaths so far - all except three being Britons - is climbing steadily . Its eventual impact on the health of the human population and the cost to the NHS, is almost impossible to measure. Yet when the cattle disease first emerged in 1986, government advisers dismissed any threat to people.

Now Europe quakes . Scientists believe that countries, such as Germany, which profess not to have BSE, are likely to have some cattle suffering from it even if the disease has not yet taken sufficient hold for it to be obvious. The first known case of BSE, in a cow on a farm in Pitsham, Sussex, occured in December 1984 , almost two years before the disease was identified. In fact, the illness may have begun to set in during the early 1970s, but at such a low level that vets and farmers did not recognise it as a new disease.

Feeding practices, in dairy farms particularly, where cows' diets included the ground remains of other cattle and sheep, probably sent the disease into its catastrophic spiral. Even now cases in Britain far outstrip those anywhere else. There have been more than 177,000 cases, nearly 780 confirmed so far this year. By contrast, Ireland has had a total of 489 BSE cases, Portugal nearly 350 and Switzerland 365 .

France, with whom the beef war drags on ,has had just over 100 cases, with 28 this year. There have also been two cases of human BSE in that country and one in Ireland.

There have been numerous forecasts about the eventual human death toll. Some estimates, putting it at less than 100, already look too optimistic. Others have judged it be hundreds of thousands. Oxford statisticians earlier this month painted a worst case scenario of 136,000 .

After years in which warnings of death through eating infected meat met public scorn, in March 1995 the fatalities began. But it was March 1996 before scientists made the first connection. The first victim to die was Stephen Churchill, aged 19, though the first person to show symptoms is thought to have been a 50-year-old, in January 1994.

Even now it is thought victims are most likely to have been infected by exposure to cheap meat-cuts from highly infective parts of cattle before the first anti-BSE controls to protect human health were in troduced in 1989. The agriculture minister, John MacGregor, banned the use of certain offal in food against the earlier advice of civil servants.

Even though the ban was not as rigorously observed as it should have been over the next six years, the measure probably stopped the collapse of the beef and dairy industries in 1996 when the link to human deaths was made, and reduced the prospects of a far worse human death toll from infected beef when BSE was at its height in the early 1990s. Other measures have been added, including from December 1997, for two years, a ban on selling beef on the bone.

Measures to stop humans spreading the disease have included changes to blood transfusions, the use of more disposable equipment and more rigorous sterilisation.

The problem for the government, even after the new findings suggesting human BSE might be spread more easily than had been assumed, is deciding just how much should be spent on seeking to prevent an unquantified risk.

The latest research means the assumptions - that a species barrier between humans and the animals they eat would cut the number of people who might succumb to BSE, and that there might have to be a high dose of infective material to induce the disease - must be re-addressed . Cows appearing healthy may also be capable of infecting people more easily than had been supposed. So scientists will have to consider whether they are removing enough offal from the food chain and whether barring cattle over 30 months for sale is sufficient. Cattle far younger than 30 months have displayed BSE signs - although not since 1996 - and the 30-month rule does not apply in many other countries that have BSE.

European-wide offal bans are only just being introduced, and scientists have suggested that just one cow slipping through the net could infect up to 500,000 people .

There is also the suggestion that transmission of BSE-like diseases through different species may create new, more virulent strains . Some scientists believe that scrapie, a BSE-like disease in sheep not known to be harmful to humans, is now disguising the BSE agent that has entered sheep through animal feed and been recycled through the generations. Scrapie-infected sheep brains are being tested with mice in the laboratories. Last month, the food standards agency suggested such a BSE-like strain might be identified "at any moment".

Contingency plans , including altering slaughterhouse and butchery practices, are already being prepared to try to avert another food panic. Britain does not routinely test for BSE in cattle planned for human food. And, unlike other countries, the UK does not destroy all the animals of a herd when a BSE case is identified.

Millions of cows over 30 months old have been destroyed under compensation schemes, and there is a suspicion that this has made it look as if BSE is dying out faster than it really is.

The recent research suggests cattle can harbour the disease it without showing outward signs of it. Random tests on 3,000 cows last year revealed 18 had BSE without showing clinical symptoms . Such checks will be increased to 10,000 this year and there will be surveys on 3,000 animals which die unexpectedly on farms or have to be slaughtered through illness or injury.

But ministers will have to consider whether also to check animals going into the food chain. That could improve consumer confidence - but not if the monitoring shows BSE is more widespread .

The government plans to follow France and Switzerland by introducing rapid cattle post mortem examinations from January with results in one to two days.

The problem is whether these will be sensitive enough to detect BSE in its early stages. Such measures would assume that the eating of infected meat has been the cause of variant CJD.

But billions of pounds-worth of preventative measures are already in place. And the question remains, how much more needs to be spent?

29 Aug 00 - CJD - Scientists find new BSE links

James Meikle

Guardian ... Tuesday 29 August 2000

Scientists are to re-examine controls against variant CJD, the deadly human form of BSE, in the wake of evidence that the disease might be highly infectious even when unwitting carriers do not display outward signs of suffering from the condition.

They will also determine whether a new system of checks on sheep , pigs and chicken is needed to ensure that recently banned farming methods have not created other potentially fatal routes for BSE to enter humans.

New research has raised fears that animals thought to be healthy and incapable of acquiring BSE could in theory pass the disease on. The results have also renewed concerns that humans not displaying vCJD symptoms but incubating the condition may infect others undergoing medical or dental procedures .

Experiments on mice and hamsters have suggested that similar diseases could jump between species more easily than had been supposed and spread within species even when obvious symptoms are not yet evident.

Although scientists in the field of BSE research have suspected this, Professor John Collinge, who headed the research funded by the medical research council, said its results could have important public health implications .

The latest developments come amid signs that the incidence of vCJDis growing at between 20% and 30% a year. In Britain , 70 people have died and nine others are still alive suffering the always fatal condition. There have been two deaths in France and one in Ireland. All are thought to have been infected years ago through exposure to cheap meat from parts of cattle containing high concentrations of the agent responsible.

Since 1989, the government has introduced a series of controls including a ban on certain offals entering food, a bar on all cattle over 30 months old being used for food, and an end to feeding cow and sheep remains to other meat-producing livestock.

Anti-vCJD measures to lower the risk of spread between humans have included tighter restrictions on blood transfusions , more use of disposable surgical instruments and better sterilisation of other equipment.

BSE-like diseases are believed to be caused by abnormal proteins, called prions, taking hold in previously healthy parts of the body's central nervous system. But "species barriers" between types of animal were believed to reduce the apparent potency. There was thought to be a high one between hamsters and mice.

Prof Collinge's team, based at the MSC's prion unit and the Imperial College school of medicine at St Mary's Hospital, London, found that mice injected in the brain with hamster scrapie, a BSE-like disease, carried high levels of infectivity while living into old age and showing no outward signs. But when material from the brains of these mice was injected into other mice and hamsters, it eventually killed them. The suspicion is that the process created a new strain, or strains, of more virulent disease .

The findings, published last night in the Proceedings of the National Academy of Sciences, will cause concern that contaminated material from people not displaying vCJD symptoms but incubating the condition may infect others undergoing medical or dental procedures through the use of contaminated instruments .

Present sterilisation and cleaning techniques cannot remove all traces of the vCJD agent , although experts say they can substantially reduce levels of infectiousness.

The new research will also reinforce suspicions that far more cattle have been infected than has been obvious and that scrapie in sheep, never known to have been harmful to humans, may have changed into a more dangerous strain by passing through cattle and back to sheep in the years when cannibalistic feeding practices were commonplace.

So far BSE has not been known to have transferred to sheep or pigs outside the laboratory, but there are likely to be renewed calls for spot checks on healthy animals to see if their brains contain signs of the disease.

Prof Collinge said: "I don't want to raise alarms that that is likely, but we could check that quite easily so why don't we? We don't want to find this out later."

He is a member of the government's spongiform encephalopathy advisory committee (Seac) which will consider the implications of the finding at the end of September. He does not think other new controls to stop infection from "hidden BSE" in cattle will be necessary, but he is "not sure" . He said: "My own view is that probably the 30-month rule and the offal ban would still protect us from that but I am not sure. This data shakes me up a bit ."

Professor Peter Smith, acting chairman of Seac, said the findings were of "considerable interest" but it was not clear that they indicated additional controls were needed.

The Department of Health said: "Current measures to protect public health from farm to healthcare were introduced on the basis that infection in animals and in people may be present in the absence of clinical diseases."

The Ministry of Agriculture said: "We believe the safeguards in place at the moment are adequate to deal with the issues Prof Collinge raises, but of course we will listen to what he has to say."

Frances Hall, secretary of the Human BSE Foundation, whose son Peter died from variant CJD in 1996, said: "We have always been worried that BSE might be in animals that aren't showing any symptoms. Subclinical animals can look perfectly fine, as can victims of human BSE before they get unwell."

(French officials have discovered three new cases of mad cow disease , the country's agriculture ministry said in a statement yesterday.)

29 Aug 00 - CJD - New fears raised over hidden type of BSE

By Nigel Hawkes, Health Editor

Times ... Tuesday 29 August 2000

British scientists raised new fears yesterday that the human version of BSE has spread to far more people than originally suspected .

They have discovered that animals can carry the brain disease without showing any symptoms, with the implication that the same is true of human beings .

The findings raise concerns that apparently healthy cows could have been harbouring BSE without falling ill and have entered the food chain.

The research also suggests that people could unwittingly spread the human version , variant Creutzfeldt-Yakob disease (vCJD), through surgical instruments or blood products . While the disease they carry may not affect them, it might develop in other patients.

The discovery that the disease can be present in a brain without displaying symptoms was made by a team at St Mary's Hospital in Paddington, London, led by John Collinge, one of Britain's leading researchers in the field.

BSE, CJD and related diseases are caused by proteins called prions in the brain. The symptoms are believed to be caused by the prions choosing to fold up into an aberrant, three-dimensional structure for an unknown reason, affecting functioning of the brain.

In the St Mary's experiments, the team were trying to infect mice with prions from hamsters. By doing experiments of this type, it is possible to work out the "species barrier" - the degree of difficulty a prion from one species has in infecting another, which is important since it has a bearing on the risk of humans getting vCJD by eating BSE-contaminated beef.

They found that the mice showed no signs of disease, but closer examination revealed that their brains had high levels of aberrant prions. This was a surprise, because it has long been believed that hamster prions could not infect mice, even if injected directly into the brain, as they were here. It has been seen as a classic example of a robust species barrier.

"This undermines a lot of our confidence in the species barrier ," Professor Collinge said. "It suggests that it is possible to suffer from sub-clinical forms of these diseases - when the brain is full of prions but they seem to be having no effect."

The data, published in the Proceedings of the National Academy of Sciences today, have been passed to the Government's expert panel, the Spongiform Encephalopathy Advisory Committee, which will consider them next month. Professor Peter Smith, the committee's acting chairman, said that the new findings will be considered at its next meeting.

Professor Collinge said that if subclinical BSE existed in cows, he hoped that it would be picked up by the rules designed to prevent pre-clinical cases entering the food chain: the 30-month rule and the offal ban. "I think the measures already in place remain adequate," he said, "but we also have to wonder if there are asymptomatic carriers of CJD in humans ."

The finding also creates a new puzzle. Until now, it had been assumed that what damages the brain is the formation of insoluble "plaques" of prion material converted to the rogue form. Professor Collinge's mice have brains full of the material, but are normal.

"They have levels of prions as high as mice dying of the disease, but no symptoms," he said. "Why?"

29 Aug 00 - CJD - Cattle may have BSE without symptoms for years

By Steve Connor, Science Editor

Independent ... Tuesday 29 August 2000

Government advisers on "mad cow" disease are to investigate fresh evidence that cattle can be badly infected with bovine spongiform encephalopathy (BSE) for years without showing any symptoms.

New research has shown that certain strains of prions, the infectious agents thought to cause BSE, can infect laboratory mice yet the animals never develop the disease.

The findings indicate that BSE can exist in a "sub-clinical" form, where high levels of infectious agent are present in an animal yet fail to result in any symptoms. The same may also be true of variant Creutzfeldt Jakob Disease, vCJD, the human equivalent of BSE.

Sub-clinical disease is different from the incubation period for BSE, when relatively low levels of the prion agent begin to build up and spread within an infected animal, eventually to cause symptoms.

Professor Peter Smith, the acting chairman of the Spongiform Encephalopathy Advisory Committee, said the latest findings, published in the Proceedings of the National Academy of Sciences, are of "considerable interest" and will be discussed in detail when it meets at the end of next month.

The research, by scientists at the Medical Research Council's prion unit, based at St Mary's Hospital in London, demonstrated that mice remain healthy when infected with large amounts of prions from infected hamsters.

Previous research had shown that mice never develop the disease when injected with hamster prions, leading scientists to believe that there was a large "species barrier" protecting mice from this source of infection.

Furthermore, when infective material from the symptomless mice was subsequently injected into other mice, these animals did develop symptoms, suggesting that a new strain of prion had been created .

John Collinge, the leader of the research team, said that the results show that just because a species appears resistant to BSE, it does not mean that they are free of infection . "This research raises the possibility, which has been mentioned before, that apparently healthy cattle could harbour, but never show signs of, BSE," he said.

Professor Collinge said current measures to protect the public from BSE did not need to be changed, but he wanted to see a national system of testing brains of cattle